Question about Cars & Trucks

1 Answer

I have a project jeep I am struggling to figure out. It is backfiring when I get to a high RPM and am assuming I have a problem with my air fuel mixture. It is a TBI (fuel injected), any ideas on how I adjust the air fuel mixture?

Posted by on


1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 20 achievements.


    An expert that got 10 achievements.


    An expert that got 5 achievements.

  • Cars & Trucks Master
  • 2,431 Answers

Back fire at a higher RPM?you need to look at the distributor,the internal part, the reluctor may have shifted causing the TBI to fire before the intake,

Posted on Nov 08, 2012


6 Suggested Answers

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

a 6ya Mechanic can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repair professionals here in the US.
click here to Talk to a Mechanic (only for users in the US for now) and get all the help you need.

Posted on Jan 02, 2017

  • 6982 Answers

SOURCE: jeep wrangler stalls out

check idle air control, tps & map sensor. As usual with electronics, test test test before buying anything/

Posted on Feb 18, 2009

  • 2007 Answers

SOURCE: engine starts,reaches high rpm,then slowly returns

Vacuum leaks. Check all hoses and intake bolts. Leaking EGR or plugged PCV valve. Air filter plugged. Leaking head gasket. Worn timing chain. Camshaft lobes worn. Valves burned or leaking. Fuel idle control system or sensor. Good luck!

Posted on Jul 03, 2009

  • 1 Answer

SOURCE: mercedes benz 190e 1900year /air flow meter connections

Guys i just bought my first car and its a Mercedes 190E 1.8L 1991. Now i noticed an digital meter just above my steering wheel with 2 knobs on each end. I dont know what is it for can u tell me plzz. Thanks :>

Posted on Jul 13, 2009

  • 1392 Answers

SOURCE: need diagram of fuel injection for 85 4x4 22re

Sounds like you have a vacuum leak somewhere. There may be a stop adjustment on the throttle body, but usually high idles are due to unmetered air entering the system.

Posted on Jul 14, 2009

  • 432 Answers

SOURCE: how to adjust air fuel mixture

On any carburator,one screw is for the idle speed, the other the air/fuel mix.Start the engine and let it get plenty warmed up. Adjust the idle screw to make the engine run slow. Turn the air/fuel screw in until the engine starts to die then out till it starts running loady.You want the screw between these two locations. Adjust it till the engine runs the fastest. Now adjust the idle speed screw to about 1000 RPM.
I hope this helps you.

Posted on Sep 24, 2009

Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

If a full a rpm cost backfire

If what you are saying is that when you reach maximum rpm the car backfires, first be aware that most ignition modules have two sections--one for low rpm and one for high rpm. Could be bad ignition module. Also possible that some tune up item (plug wires, dist. cap) is bad, or that the engine is running too lean at high rpms (bad fuel pump, dirty filter, etc.)

Aug 11, 2015 | Cars & Trucks

2 Answers

Why does my truck backfire thru the carborater when it is hot outside?

A backfire is caused when your intake valve/s aren't closing completely before ignition in the cylinder. This ignites any fuel/air mixture left in the intake manifold. Fine tune your timing.

Aug 15, 2012 | Cars & Trucks

1 Answer


For this types of problem,there are few help inks to troubleshoot the problem.Click the link below to go through the troubleshooting procedure to resolve the issues :----Idles rough and quits when gas pedal is pressed less? idles rough?
--------------runs lean and idles rough?
-----------Car still runs Rough after tune up?
------------Idle flair is noticed on car? Rough idle? car will not idle? Erratic idle speed?
----------High rpm in neutral? Inconsistant high RPM in neutral?
------------Engine Backfires? Nissan stalls and bucks on Acceleration?

Nissan Pathfinder Backfires?
---------How to adjust rpm?
------------Engine cuts out at 3000 RPM?
----------This will help.Thanks.

Feb 17, 2012 | 1992 Nissan Pickup

2 Answers

Car doesn't idle consistently--revs & almost cuts out

Check air idle control valve may be sticking or stuck.Clean throtlle plate with air intake cleaner and a tooth brush obviously when car is not running

Nov 13, 2009 | 1990 Subaru Legacy

2 Answers

Jeep carbuerator backfiring

check your fuel pump pressure and volume.

Aug 06, 2009 | 1988 Jeep Cherokee

2 Answers

Over reving on start up

make sure all the connectors are on the throttle body and nothing is binding. Jeeps have a service bullitin about something like this. Try removing the IAC and clean the pintal area or replace the IAC. I have a 93 wrangler and I have had this happen to me. I cleaned it and it worked. Try disconnecting the battery for a few minutes then try it again. This will reset the IAC to MIN. If this allows it to start at a lower RPM then you Isolated the problem. Try tappping on the IAC also. It may be sticking. Either way if anything make a difference then you will prabable need An IAC.Make sure you have no vacuum leaks anywhere. A vacuum leak will hold the idle higher also and the computer will close the IAC as far as possible to compensate.

Heres why you have a high RPM
When you start the car if you have a stuck open IAC or vacuum hose leak the O2 sensor will see this extra air and add fuel to compensate to maintaim a 14.7 to 1 ratio but also the computer will see your foot is off the gas and the throttle position switch is closed. Under this condition the computer will want a precalibrated RPM which is between 660 to about 750 rpm +or- some. It will close the IAC till it reaches this level.

Jul 14, 2009 | 1995 Jeep Wrangler

1 Answer

Engine starts,reaches high rpm,then slowly returns to a rough idle, misses badly,no backfire,surges as if searching/adjusting air/ fuel/est,timing light shows mark constantly changing/erratic,engine then...

Vacuum leaks. Check all hoses and intake bolts. Leaking EGR or plugged PCV valve. Air filter plugged. Leaking head gasket. Worn timing chain. Camshaft lobes worn. Valves burned or leaking. Fuel idle control system or sensor. Good luck!

Apr 18, 2009 | 1991 Chevrolet Camaro

1 Answer

02 Grand Cherokee High RPM start. Cuts out when driving

Ckean throttle plate inside throttle body...They tend to get dirtier than their counterparts in carbureted engines due to lack of fuel spray that kept them clean. If no luck with that, clean idle air control valve on TB. When doing this, don't turn the plunger, just clean with carb spray and replace. do not loose "o" ring seal.
Good luck

Mar 20, 2009 | 2002 Jeep Grand Cherokee

Not finding what you are looking for?

Open Questions:

Cars & Trucks Logo

Related Topics:

41 people viewed this question

Ask a Question

Usually answered in minutes!

Top Cars & Trucks Experts


Level 3 Expert

77201 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22265 Answers

Randy Ohler

Level 3 Expert

14585 Answers

Are you a Car and Truck Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides